onsemi NCP161BFCS280T2G

Overview

NCP161BFCS280T2G from onsemi is a 450 mA ultra-low-noise, high-PSRR LDO regulator with fixed 2.8 V output, ±2% accuracy over load/temperature, 150 mV dropout at 450 mA, and 10 µV_RMS output noise - designed for RF and analog circuits in battery-powered smartphones and wireless LAN devices.

For engineers reviewing the NCP161BFCS280T2G datasheet, pinout, applications, or equivalent options, this page delivers verified package mapping (WLCSP4, 0.64 mm × 0.64 mm), validated thermal shutdown (160°C), confirmed active-discharge exclusion, and real-world transient response data for low-noise power rail design.

Technical Context

The NCP161BFCS280T2G uses a PMOS pass transistor architecture enabling ultra-low dropout and inherent reverse-current protection. Its bandgap reference and integrated soft-start ensure stable startup under light and heavy loads without external compensation.

Unlike versions with active discharge (e.g., "A" suffix), the "B" variant omits the internal 280 Ω discharge path - confirmed by datasheet Section 14 (Enable Operation) and ordering table distinctions - resulting in no intentional output pull-down during disable, critical for systems requiring hold-up voltage retention.

Key Specifications

Pinout & Package

Package: WLCSP4 (0.64 mm × 0.64 mm × 0.33 mm), Pb-free, RoHS-compliant, bottom-exposed pad tied to GND for thermal relief.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with NCP161BFCS280T2G, the XC6210B282MR-G trades 25% lower output current and 2.5× higher noise for mature SOT-25 availability, while the RT9080AL-28PUF adds active discharge and 50 mA headroom at the cost of incompatible shutdown behavior and reduced thermal efficiency.

Availability

NCP161BFCS280T2G is available at Aetrix Electronics and suitable for smartphone RF front-end, Wi-Fi 6E transceiver bias, and industrial IoT sensor node applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for NCP161BFCS280T2G includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi (Nasdaq: ON) is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The NCP161 series targets ultra-low-noise, high-PSRR power delivery for RF and precision analog circuits - specifically engineered to replace legacy LDOs in next-generation mobile and wireless infrastructure where spectral purity and battery efficiency are critical.

FAQ

What is the output voltage tolerance of the NCP161BFCS280T2G across temperature and load?

The NCP161BFCS280T2G maintains ±2% output voltage accuracy over the full operating temperature range (−40°C to +125°C) and across its entire 0–450 mA load range, as specified in the Electrical Characteristics table (page 4). This tolerance applies to both WLCSP4 and XDFN4 packages and is guaranteed without external trimming or calibration. The NCP161BFCS280T2G achieves this stability through an integrated bandgap reference and precision feedback network.

Does the NCP161BFCS280T2G include active output discharge functionality?

No, the NCP161BFCS280T2G does not include active output discharge. The "B" prefix explicitly denotes the non-active-discharge variant, confirmed in the Ordering Information table (page 17) and Application Information section (page 14). Unlike "A"-suffix versions, it lacks the internal 280 Ω discharge path - meaning the output remains floating when disabled, preserving voltage on downstream hold-up capacitors. This behavior is intentional and documented for system-level power sequencing control.

What is the minimum input voltage required for the NCP161BFCS280T2G to regulate at full 450 mA load?

The NCP161BFCS280T2G requires a minimum input voltage of 2.975 V to maintain regulation at 450 mA load, calculated from its typical 175 mV dropout voltage plus nominal 2.8 V output (2.8 V + 0.175 V = 2.975 V). The datasheet specifies 175 mV typical and 290 mV maximum dropout at 450 mA for 2.8 V output in WLCSP4/XDFN4 packages (page 4, Dropout Voltage table), so design margin should target ≥3.1 V input for robust operation across process and temperature variation.

Which ceramic capacitor dielectrics are recommended for use with the NCP161BFCS280T2G?

X7R and X5R ceramic dielectrics are explicitly recommended for both input (C_IN) and output (C_OUT) capacitors per the Applications Information section (page 14). These dielectrics provide stable capacitance over temperature (±15% for X7R, ±15% for X5R) and low voltage coefficient - critical because small-case MLCCs (e.g., 0201) suffer significant capacitance loss under DC bias. The NCP161BFCS280T2G is stable with ≥0.7 µF effective output capacitance, but 1 µF is the recommended value to accommodate derating.

How does the thermal performance of the NCP161BFCS280T2G compare between WLCSP4 and other packages?

The NCP161BFCS280T2G in WLCSP4 package achieves R_JA = 108°C/W (junction-to-ambient), significantly better than XDFN4 (198.1°C/W) and SOT23-5 (218°C/W), as listed in the Thermal Characteristics table (page 3). This 45–50% improvement stems from the WLCSP4's bottom-exposed thermal pad, which must be soldered to a PCB ground plane. With 2 oz copper and 400 mm² thermal pad area, the WLCSP4 variant supports up to ~1.1 W max power dissipation at 25°C ambient - enabling higher continuous load capability in space-constrained designs.